JP7454445B2 - Electric vehicle charging device - Google Patents

Description

The present invention relates to an electric vehicle charging device that charges a storage battery (battery) of an electric vehicle.

Conventionally, for example, Patent Document 1 discloses an electric vehicle charging device. This electric vehicle charging device includes an AC/DC power converter that converts alternating current power (AC power) into direct current power (DC power), and a socket connected to the output side of this AC/DC power converter. are doing. A plug connected to one end of the charging cable is detachably connected to the socket. A connector that is detachably inserted into the charging port of the electric vehicle is connected to the other end of the charging cable via a cable-installed charging control device. The cable-installed charging control device monitors charging of a battery mounted on an electric vehicle, provides acquired charging-related information to a terminal device, and controls battery charging. A temperature sensor is provided within the plug to measure the temperature of the plug pin.

Then, the DC power output from the AC/DC converter is input to the charging cable via the plug connected to the socket. The input DC power is output from the connector via the cable-installed charging control device. The output DC power is input from the charging port of the electric vehicle, and the battery is rapidly charged. During quick charging, if the temperature of the plug pin measured by the temperature sensor is above a certain level, the cable-mounted charging control device determines that the plug pin is overheating, and reduces the charging power or interrupts charging. Perform control for

JP2016-63737A

The electric vehicle charging device disclosed in Patent Document 1 monitors the temperature of the plug connected to one end of the charging cable, and if the plug is overheated, controls to reduce or interrupt the charging power to prevent the plug from heating. This prevents fires from occurring, but there is an issue with the longer charging time.

In recent years, from the viewpoint of convenience, there has been a demand for shortening the charging time of electric vehicles using quick charging devices. In order to shorten the charging time, the charging current may be increased. However, if the charging current is increased, the wire diameter of the charging cable for transmitting the charging current becomes thicker, making operability difficult. On the other hand, if the charging current is increased without increasing the wire diameter of the charging cable, the cable temperature may rise and the cable may deteriorate, so it is necessary to cool the cable. However, regarding cable cooling, there are disadvantages in terms of price, such as the use of liquid-cooled cables.

Charging cables used in quick charging devices for electric vehicles have a rated current specified from the viewpoint of safety, and charging cannot exceed the rated current. However, recent research has shown that even if an increased current exceeding the rated current (hereinafter referred to as "boost current") is passed through the charging cable, if the cable temperature does not exceed the allowable upper limit temperature, there may be safety issues. It has been proven that there is no.

Therefore, the electric vehicle charging device of the present invention employs the following configuration in order to charge the battery using boost current while ensuring safety.
That is, the electric vehicle charging device of the present invention includes an AC/DC power converter that converts AC power into DC power based on a charging current command and generates a charging current for charging the battery of the electric vehicle, and a charging cable having a charging connector connected thereto, transmitting the charging current to the charging connector side and charging the battery via the charging connector; and a cable temperature sensor detecting the cable temperature of the charging cable; Based on the cable temperature detected by the cable temperature sensor, if the cable temperature is lower than an allowable upper limit temperature, the battery is charged with a boost current exceeding the rated current of the charging cable. and a charging control section that outputs the charging current command to control the AC/DC power conversion section.

The present invention makes it possible to charge with a boost current that exceeds the rated current of the charging cable, thereby shortening the charging time of the battery installed in the electric vehicle. This significantly improves convenience.

A schematic circuit diagram showing the configuration of an electric vehicle charging device in Example 1 of the present invention A pattern diagram showing a charging sequence (charging control based on time conditions) using the charging device 1 of FIG. 1 A pattern diagram showing a charging sequence (charging control under cable temperature conditions (1)) using the charging device 1 in Figure 1 A pattern diagram showing a charging sequence (charging control under cable temperature conditions (2)) using the charging device 1 in Figure 1 A pattern diagram showing a charging sequence (charging control (protection) under cable temperature conditions) using the charging device 1 in Figure 1 A pattern diagram showing a charging sequence (charging control under ambient temperature conditions (1)) using the charging device 1 of FIG. 1 A pattern diagram showing a charging sequence (charging control under ambient temperature conditions (2)) using the charging device 1 of FIG. 1 A pattern diagram showing a charging sequence (charging control (protection) under ambient temperature conditions) using the charging device 1 in Figure 1 Flowchart showing the charging operation in the charging device 1 of FIG. 1

Modes for carrying out the invention will become apparent from the following description of preferred embodiments when read in conjunction with the accompanying drawings. However, the drawings are solely for illustrative purposes and do not limit the scope of the present invention.

(Configuration of Example 1)
FIG. 1 is a schematic circuit diagram showing the configuration of an electric vehicle charging device in Example 1 of the present invention.

This electric vehicle charging device (hereinafter simply referred to as "charging device") 1 converts AC power supplied from an AC power source 20 into DC power, and connects a charging connector 22 connected to a terminal of a charging cable 21 to an electric vehicle. This is a device for rapidly charging a battery 25 mounted on an electric vehicle through a charging port 24 of the electric vehicle. The charging connector 22, also called a charging gun, is detachably inserted into the charging port 24 of an electric vehicle, and has a cable temperature sensor 23 near the internal contact for detecting the temperature of the charging cable 21. is built-in. The cable temperature sensor 23 is composed of a temperature sensing element such as a thermistor whose resistance value changes depending on the temperature.

The charging device 1 has an input section 2 that inputs AC power, and an AC/DC power conversion section 3 and an output section 4 are connected in series to the output side of the input section 2. The AC/DC power conversion unit 3 converts the AC power input from the input unit 2 into DC power, and converts it into a normal rated current, a boost current exceeding this rated current, or a stopped state based on the charging current command S13. It outputs one of the zero currents. The output section 4 sends the output current of the AC/DC power conversion section 3 to the charging cable 21.

The charging device 1 is further provided with an operation section 5, an ambient temperature sensor 6, and a charging control section 10. The operation unit 5 is used to input information such as starting and stopping charging, and is composed of a keyboard and the like. The ambient temperature sensor 6 detects the ambient temperature inside or outside the charging device 1, and is composed of a temperature sensing element such as a thermistor whose resistance value changes depending on the temperature.

The charging control unit 10 provides a charging current command S13 to the AC/DC power converter 3 to control the output current of the AC/DC power converter 3, and includes a cable temperature measuring unit 11, an ambient temperature measuring unit 12, a charging current command section 13, and the like. The cable temperature measurement section 11 measures the cable temperature of the charging cable 21 from the output signal of the cable temperature sensor 23 and provides this cable temperature to the charging current command section 13 . The ambient temperature measuring section 12 measures the ambient temperature of the charging device 1 from the output signal of the ambient temperature sensor 6, and provides this ambient temperature to the charging current command section 13.

The charging current command unit 13 inputs the measured cable temperature and ambient temperature, and determines whether the cable temperature is an allowable upper limit temperature (for example, a cable temperature Kmax1 at which boost mode charging can be continued or a cable at which boost mode charging can be started). temperature Kmax2) or the ambient temperature is lower than the allowable set temperature (for example, the ambient temperature Lmax1 that allows boost mode charging to continue, or the ambient temperature Lmax2 that allows boost mode charging to start), the rating of the charging cable 21 A charging current command S13 for performing "boost mode charging" exceeding the current is output, and during charging, the cable temperature is set to the allowable upper limit temperature (for example, cable temperature Kmax3 for abnormality determination) or the ambient temperature. exceeds the allowable set temperature (for example, the ambient temperature Lmax3 for abnormality determination), detects a temperature abnormality, outputs the charging current command S13 to "end charging", and activates the AC/DC power converter 3. It has a control function. Furthermore, the charging current command unit 13 includes a charging time measuring unit (for example, a timer) 13a that measures the charging time for the battery 25, and determines the charging time by the boost current based on the charging time measured by the timer 13a. When the upper limit time (for example, boost mode charging maximum time Tmax) is exceeded, it has a function of outputting a charging current command S13 for "rated current charging" to control the AC/DC power converter 3.

The charging control unit 10 having such a charging current command unit 13 is constituted by a processor having a central processing unit (CPU) and individual circuits such as semiconductor elements.

(Operation of Example 1)
2A to 2G are pattern diagrams showing a charging sequence using the charging device 1 of FIG. 1. In each of FIGS. 2A to 2G, the horizontal axis represents the charging time, and the vertical axis represents the charging current (A), and the following control is performed under the control of the charging control unit 10.

The pattern diagram in FIG. 2A shows a charging sequence (charging control under charging time conditions). For example, the set charging time is 30 minutes. First, charge in boost mode with a boost current that exceeds the rated current, and when the maximum boost mode charging time Tmax (minutes) is reached, the charging current is limited and lowered to the rated current, and the remaining time (30-Tmax) is charged. Charge the battery for a while.

The pattern diagram in FIG. 2B shows a charging sequence (charging control under cable temperature conditions (1)). For example, the charging time is set to 30 minutes. During charging in boost mode, the cable temperature rose and exceeded the allowable upper limit temperature (for example, the cable temperature Kmax1 at which boost mode charging can be continued), so the remaining 30 minutes (30-α) , charging is limited to the rated current.

The pattern diagram in FIG. 2C shows a charging sequence (other charging control (2) under cable temperature conditions). For example, the set charging time is 30 minutes. Since the cable temperature exceeds the allowable upper limit temperature (for example, cable temperature Kmax2 at which boost mode charging can be started), the charging current is limited and charging is performed at the rated current. After α minutes, the cable temperature has dropped to cable temperature Kmax2, so charging is performed in boost mode. During charging in boost mode, when the cable temperature rises to cable temperature Kmax1, the charging current is limited and lowered to the rated current, and charging is continued for the remaining time (30-α-Tmax). That is, the charging control unit 10 performs feedback control so that the cable temperature does not exceed the upper limit temperature (for example, cable temperature Kmax1) during charging in the boost mode and subsequent charging at the rated current.

The pattern diagram in FIG. 2D shows a charging sequence (charging control (protection) under cable temperature conditions). Since the cable temperature is lower than the allowable upper limit temperature (for example, cable temperature Kmax3 for abnormality determination), charging is performed in boost mode. During charging in the boost mode, if a temperature abnormality occurs (for example, the cable temperature rises rapidly due to a short circuit accident, etc.) and the cable temperature reaches Kmax3, charging is stopped for protection.

The pattern diagram in FIG. 2E shows a charging sequence (charging control under ambient temperature conditions (1)). For example, the charging time is set to 30 minutes. When the ambient temperature is lower than the ambient temperature Lmax1 at which boost mode charging can be continued, charging is performed in boost mode. After α minutes, when the ambient temperature rises and reaches the ambient temperature Lmax1, charging is performed at the rated current for the remaining time (30-α) minutes. As a result, the ambient temperature decreases.

The pattern diagram in FIG. 2F shows the charging sequence (other charging control (2) under ambient temperature conditions). For example, the charging time is set to 30 minutes. Since the ambient temperature exceeds the allowable set temperature (for example, the ambient temperature Lmax2 at which boost mode charging can be started), the charging current is limited and charging is performed at the rated current. After α minutes, the ambient temperature has decreased to ambient temperature Lmax2, so charging is performed in boost mode. During charging in boost mode, when the ambient temperature rises to ambient temperature Lmax1, the charging current is limited and lowered to the rated current, and charging is continued for the remaining time (30-α-Tmax). That is, the charging control unit 10 performs feedback control so that the ambient temperature does not exceed a set temperature (for example, set temperature Lmax1) during charging in the boost mode and subsequent charging at the rated current.

The pattern diagram in FIG. 2G shows a charging sequence (charging control (protection) under ambient temperature conditions). Since the ambient temperature is lower than the allowable set temperature (for example, ambient temperature Lmax3 for abnormality determination), charging is performed in boost mode. During charging in the boost mode, if a temperature abnormality occurs (for example, the ambient temperature rises rapidly due to a short circuit accident, etc.) and the ambient temperature reaches Lmax3, charging is stopped for protection.

3(A) and 3(B) are flowcharts showing the charging operation in the charging device 1 of FIG. 1.
The charging device 1 of FIG. 1 performs a charging operation to the battery 25 of the electric vehicle according to steps ST1 to ST9 of FIG. 3(A) or steps ST10 to ST11 of FIG. 3(B) below.

In step ST1 of FIG. 3(A), when a charging start operation is performed using the operation unit 5 of FIG. 1, the process proceeds to step ST2. In step ST2, the charging current command unit 13 in FIG. 1 performs a boost mode charging start determination based on the cable temperature measured by the cable temperature measurement unit 11 and the ambient temperature measured by the ambient temperature measurement unit 12. When the cable temperature is lower than the cable temperature Kmax2 at which boost mode charging can be started in FIG. 2C, or when the ambient temperature is lower than the ambient temperature Lmax2 at which boost mode charging can be started in FIG. 2F, the charging current command unit 13 , determines that boost mode charging can be started (Y), outputs charging current command S13 of "boost mode charging" to AC/DC power converter 3, and proceeds to step ST3; otherwise, boost mode charging cannot be started. (N), the charging current command S13 of "rated current charging" is output to the AC/DC power converter 3, and the process proceeds to step ST6.

In step ST3, the AC/DC power converter 3 converts the AC power input from the input unit 2 into DC power, and generates a boost current larger than the rated current of the charging cable 21. The generated boost current is output from the output unit 4 to the charging cable 21 and supplied to the battery 25 via the charging connector 22 and the charging port 24 of the electric vehicle. As a result, the battery 25 is charged in boost mode, and the process proceeds to step ST4.

In step ST4, the charging control unit 10 determines whether charging of the battery 25 is completed based on, for example, a battery voltage signal sent from the electric vehicle, and when the determination result is "charging completed" (Y), step ST9. The process proceeds to step ST5 to perform charging termination processing, and when the determination result is "charging not completed" (N), the process proceeds to step ST5.

In step ST5, the charging current command section 13 performs boost mode charging based on the charging time measured by the timer 13a, the cable temperature measured by the cable temperature measuring section 11, and the ambient temperature measured by the ambient temperature measuring section 12. Make a termination judgment. When the boost mode charging time exceeds the maximum boost mode charging time Tmax in FIG. 2A, 2C, or 2F, the charging current command unit 13 sets the cable temperature Kmax1 at which the cable temperature can continue boost mode charging in FIG. 2B. or when the ambient temperature exceeds the ambient temperature Lmax1 in FIG. 2E at which boost mode charging can be continued, it is determined that the booth mode charging has ended (Y) and the process proceeds to step ST6. At other times, it is determined that the booth mode charging is not completed (N), and the process returns to step ST3 to repeat the booth mode charging and the charging completion determination in step ST4.

In step ST6, the charging current command section 13 outputs the charging current command S13 for "rated current charging" to the AC/DC power conversion section 3. Then, the AC/DC power converter 3 generates a rated current lower than the boost current. The generated rated current is output from the output unit 4 to the charging cable 21 and supplied to the battery 25 via the charging connector 22 and the charging port 24 of the electric vehicle. Thereby, rated charging of the battery 25 shown in FIG. 2A, FIG. 2B, FIG. 2C, FIG. 2E, or FIG. 2F is performed, and the process proceeds to step ST7.

In step ST7, the charging control unit 10 determines whether charging of the battery 25 is completed based on, for example, a battery voltage signal sent from the electric vehicle, and when the determination result is "charging completed" (Y), step ST9. The process proceeds to step ST8 to perform charging termination processing, and when the determination result is "charging not completed" (N), the process proceeds to step ST8.

In step ST8, the charging current command section 13 performs a boost mode charge restart determination based on the cable temperature measured by the cable temperature measurement section 11 and the ambient temperature measured by the ambient temperature measurement section 12. When the cable temperature is lower than the cable temperature Kmax2 at which boost mode charging can be started in FIG. 2C, or when the ambient temperature is lower than the ambient temperature Lmax2 at which boost mode charging can be started in FIG. 2F, the charging current command unit 13 , determines that boost mode charging can be resumed (Y), outputs the charging current command S13 for "boost mode charging" to the AC/DC power converter 3, and returns to step ST3; otherwise, boost mode charging is resumed. It is determined that it is not possible (N), and the charging current command S13 for "rated current charging" is output to the AC/DC power converter 3, and the process returns to step ST6.

In step ST10 of FIG. 3(B), when a charging stop operation is performed using the operation unit 5 of FIG. 1, the process proceeds to step ST9 under the control of the charging control unit 10, and the charging process ends. Further, in step ST11, the charging current command unit 13 determines that during boost mode charging in step ST3 of FIG. When the ambient temperature exceeds Kmax3 or when the ambient temperature exceeds the ambient temperature Lmax3 for abnormality determination in Fig. 2G, a temperature abnormality is detected and a charging current command S13 of "charging end" is output for protection. The process advances to step ST9 to end the charging process.

(Effects of Example 1)
According to the first embodiment, charging with a boost current exceeding the rated current of the charging cable 21 is possible, and the charging time of the battery 25 mounted on the electric vehicle can be shortened. This significantly improves convenience.

(Modified example)
The present invention is not limited to the first embodiment described above, and various usage forms and modifications are possible. Examples of usage patterns and modified examples include the following (a) to (c).
(a) The charging device 1 in FIG. 1 may be modified to have a configuration other than that shown in the drawings. For example, based on the cable temperature detected by the cable temperature sensor 23, if the cable temperature is lower than the allowable upper limit temperature, the charging control unit 10 uses a boost current exceeding the rated current of the charging cable 21 to charge the battery. Even if the configuration is modified to control the AC/DC power converter 3 by outputting the charging current command S13 for performing the charging of 25, substantially the same effects as in the first embodiment can be obtained.
(b) FIGS. 2A to 2G may be modified into charging sequences other than those shown.
(c) The processing content of the flowchart of the charging operation in FIG. 3 can be changed according to the modification of the configuration of the charging device 1 described in (a) above.

1 Electric vehicle charging device 3 AC/DC power conversion section 5 Operation section 6 Ambient temperature sensor 10 Charging control section 11 Cable temperature measurement section 12 Ambient temperature measurement section 13 Charging current command section 13a Timer 20 AC power 21 Charging cable 22 Charging connector 23 Cable temperature sensor 24 Electric vehicle charging port 25 Battery

Claims (6)

an AC/DC power conversion unit that converts AC power to DC power based on a charging current command and generates a charging current for charging a battery of an electric vehicle;
a charging cable that has a charging connector connected to the battery, transmits the charging current to the charging connector side, and charges the battery via the charging connector;
a cable temperature sensor that detects the cable temperature of the charging cable;
Based on the cable temperature detected by the cable temperature sensor, if the cable temperature is lower than an allowable upper limit temperature, the battery is charged with an increased current exceeding the rated current of the charging cable. a charging control unit that outputs the charging current command to control the AC/DC power conversion unit;
An electric vehicle charging device comprising: The charging control section includes:
comprising a charging time measuring section that measures charging time to the battery,
Based on the charging time measured by the charging time measurement section, when the charging time using the increased current exceeds an upper limit time, outputting the charging current command for charging the battery at the rated current. controlling the AC/DC power conversion unit;
The electric vehicle charging device according to claim 1, characterized in that: The charging control section includes:
comprising a charging time measuring section that measures charging time to the battery,
Based on the cable temperature detected by the cable temperature sensor and the set time measured by the charging time measuring section, the cable temperature exceeds the upper limit temperature while charging the battery with the increased current. and controlling the AC/DC power converter by outputting the charging current command for charging the battery at the rated current during the remaining time within the set time.
The electric vehicle charging device according to claim 1, characterized in that: The electric vehicle charging device according to claim 1 has an ambient temperature sensor that detects the ambient temperature,
The charging control section includes:
When the ambient temperature detected by the ambient temperature sensor exceeds an allowable set temperature, the battery is charged at the rated current, and if a temperature abnormality occurs during the charging, the charging outputting the charging current command to stop the AC/DC power converter;
An electric vehicle charging device characterized by: The charging control section includes:
When the ambient temperature falls below the set temperature, or when the cable temperature falls below the upper limit temperature, the charging current switches from the rated current to the increased current to charge the battery. outputting a command to control the AC/DC power converter;
The electric vehicle charging device according to claim 4, characterized in that: The charging control section includes:
When charging the battery by switching to the increased current, feedback control is performed so that the ambient temperature does not exceed the set temperature or the cable temperature does not exceed the upper limit temperature.
The electric vehicle charging device according to claim 5, characterized in that:

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